When it comes to watering your bonsai there are no hard and fast rules. Each plant is different, so it’s important to get to know your bonsai and its needs. Watering your bonsai is one of the most important parts of caring for it. Under-watering, followed by over-watering, is the most common mistake made by bonsai beginners and the reason why many beginners lose their bonsai prematurely.
When a tree is planted in the ground its roots will spread out in search of enough moisture, but when confined to a small pot this is no longer possible. Unlike trees in the ground, bonsai trees become reliant on us to give it the water it needs to thrive.
Essential Factors
To help you understand the specific watering needs of your bonsai, consider the below factors. These will affect you should approach watering your bonsai.
- Species – Deciduous Bonsai trees will often dry out more quickly, whilst Evergreens may need slightly less water in the winter.
- Size –The size of the bonsai tree will affect how much water it requires to thrive.
- Pot size –In a smaller pot, the soil will dry out quickly and your Bonsai will need watering more frequently. It’s also worth noting that if you use a ceramic pot the soil may dry out more quickly than if you were using a wooden pot.
- Climate – In hot dry climates your bonsai tree will also require more frequent watering. If you live in Arizona, your bonsai watering requirements are going to be vastly different than if you live in New York.
- Time of Year – During growth season, usually spring and early summer your bonsai will need more water.
- Soil Mixture – The soil mixture which you are using for your bonsai can affect the amount of moisture your bonsai requires. Organic substrates tend to retain more moisture than other soil substrates. If you would like to know more about soil mixtures check out our Ultimate Guide.
How to Water a Bonsai Tree
How Often Should I Water My Bonsai?
You should check your Bonsai daily. To check if it is time to water, place your finger approximately 1 cm into the soil. If the soil feels almost dry underneath, then it’s time to water. If you’d rather not use your fingers, you could get a wooden chopstick (must be untreated). Push it down into the soil and leave it for around 10 minutes, if it comes out with a watermark or darkened your soil is still moist. If the chopstick is dry or relatively unchanged then it’s time to water. Never allow your Bonsai soil to completely dry out. You can also buy a Bonsai moisture meter which will read the moisture levels in the soil for you.
When Should I Water My Bonsai?
A great time to water your bonsai would be first thing in the morning. If not, then the evening. As with most things that you care for, your bonsai will appreciate some consistency, so once you get to know your bonsai and how much water it requires, make a little schedule!
What Type Of Water Should I Use To Water My Bonsai?
Rainwater is the optimum choice of water for your Bonsai, it is pure and is great for washing away any buildup of salt from your Bonsai soil. Leave a container out overnight to collect some fresh rainwater. If rainwater is not possible then tap water will be fine, if you are able to drink it. If your tap water is heavily chlorinated fill your container and leave it sitting overnight. The chlorine will evaporate and in the morning your water will be fine for your Bonsai.
Bonsai Watering Methods
When watering it is extremely important that all the soil is soaked and not just the top layer. There are two ways you can water your Bonsai tree that can achieve this.
Top Down
The first option is to use a watering can or a hose but be cautious with the power of the nozzle, you want to use a fine spray nozzle. This should emulate natural rain. A great tip when watering this way is to spray the soil a little at first to wet it, then go ahead and water it well. This helps the soil prepare to absorb a large quantity of water. If you choose to water your plant using the overhead method always ensure you are providing enough water, you should see water draining from the bottom of the pot.
Immersion
The alternative method is to dunk your Bonsai tree. To do this you need to immerse the pot in water up to the rim where you should leave it for about half an hour. This is a good way to ensure that all the soil is going to get wet and is especially good if your Bonsai has dried up and needs rescue!
Misting
Sometimes it’s hard to keep the humidity levels high enough for a bonsai to stay healthy. This is more common indoors or in the middle of summer in hot areas. It’s a good practice to mist your bonsai trees to make up for the dry environments. Not only does it keep your trees hydrated, but misting can also clean the leaves and keep your bonsai healthy. This isn’t mandatory, but some species will do better with daily misting.
Don’t Over-Water
It is important to note that overwatering is potentially more damaging to your plant than under-watering although both are obviously detrimental and either left unchecked will result in shortening the life of your bonsai tree.
Overwatering can be hard to detect, when overwatered the fine roots of your bonsai will be suffocated and will begin to die off. Often, bacteria will begin to grow. Some signs include the yellowing of the foliage, the shrinking of branches, and the stems dying.
Signs of underwatering may include yellow or brown leaves and dry soil.
Watering Your Indoor Bonsai
Humidity is another vital component that must be considered. Tropical and subtropical bonsai, which are often grown indoors require a humid environment. This is very important to remember throughout the winter. A couple of good ways to help with the lack of humidity would be keeping a mist bottle, filled with room temperature water, next to your bonsai. Give it a little mist a few times a day.
Alternatively, you can sit your bonsai tree in a gravel-filled tray then add a little water. Ensure that the pot sits on the gravel, you don’t want the drainage holes at the bottom of the pot sitting in the water. As it evaporates around your tree it will give a little humidity to your Bonsai.
Conclusion
We hope this guide has answered all of the questions you have in regards to watering your bonsai tree. You can contact us if you have any questions. Also, ask for advice from local garden centers. If you’re interested in some of the more scientific elements of plant watering, here is a very detailed article from nature.com. It has illustrations, pictures, and specific breakdowns of the process.